POPULATION ECOLOGY OF PEARL OYSTER PINCTADA MARTENSI IN THE VICINITY WATERS OF NUCLEAR POWER STATION AT DAYA BAY
ZHENG Cheng Xing HUANG Zong Guo LI Chuan Yan WANG Jian Jun LIN Na (Third Institute of Oceanography,SOA, Xiamen 361005, China)
The observation on the growth of shell height and mortality of Pinctada martensi was carried out in Dongshan Pearl Oyster Mariculture Farm during the period from July, 1993 to December, 1994. This paper reports the growth of shell height, population structure, mortality and the differences among observed groups at different periods.The results are shown as following: 1. Increment in shell height: The trend for the growth of shell demonstrated that the highest growth rate occurred in small size shells or larva shells with height less than 40 mm,in which the height increment may be much as 25.0 to 32.8 mm. The growth rate was slowing down for middle size shells with heights of 40 to 50 mm, in which the increment ranged from 8.9 to 12.8 mm. The growth rate was lowest for adult shells with heights between 50 to 60 mm. Thus, the decreasing growth rate exihibits in the order of larva or small shells,middle size shells and adult shells. 2. Population structure: The shell heights tended to show the normal distribution for the early stage of population ( Fig. 1 ), during which 70% of individuals dominated thea same height. With the growth and death of individuals, the normal distribution comes to be vague or deformed. 3. Mortality: The mortality was lowest for the post-spat,then for early spat,middle size shells, adult shells and nucleared shells in sequence. The survival rate showed in the other way in order. The post-spats showed hightest survival rate of 29 4% and nucleared shells showed only 3 7%(Tab. 4). 4. There was no direct impact of warm water to the Pearl Farm. However, due to the inflow of great amount of silt from surounding waters, the depth of water at the farm is getting shallower. Besides, the factors such as living sewage due to population increase, entrophication resulting from shrimp pond discharge etc. may undoublely threaten the growth of Pinctada martensi. The environmemtal variations and the state of warm water covering areas resulting from the discharged warm water from the nuclear power station in Daya Bay are preliminarily described.
【CateGory Index】： Q958.15